Pressure fluid servomotor for reversing gears



Nov. 15, 1949 w. WAGNER ET AL 2,488,045

PRESSURE FLUID SERVOMOTOR FOR REVERSING GEARS Filed Jan. 30, 1946 2 Shez ats-Sheet l RK'NNF' Q 7 45 46 j R'crN ForN- 32 zjv I la 0 8 o INVENTORS WILL/AM WAGNZR JOHN SWAMN Nov. 15, 1949 w. WAGNER ET AL PRESSURE FLUID SERVOMOTOR FOR REVERSING GEARS 2 Sheets-Sheet 2 Filed Jan. 50, 1946 7 2. 2 I A a J. a a y 5 w i i Patented Nov. 15, 1949 PRESS'UREFLUID SERVOMOTOR FOR REVERSING GEARS Williamv Wagner. and John SwanmVancouver; British Columbia, Canada ApplicationeJanuary 30, 1946, Serial No. 644,238"

7 Claims. (Cl; 121-38) Our invention relates to improvements in remote controls for reversing gears and the like.

The objects of the invention are to provide a control device operated preferably bycompressed air for moving a member between threepositions, which in the instance described, represent a forward drive position, a neutral position and a reverse drive position; to provide a definite movement of the member from either end position or the forward orreverse position to intermediate, or neutral positions, and to provide a system whereby no-fluid pressure is applied-to any part of the control after the manually operable control lever is released, so that the parts cannot creep incidental to leakage or any other defect and cause an unwanted movement of the control parts.

The invention consists of a cylinder having a reciprocating piston thereon, said piston being connected to a rocking part and means for arresting the movement of the piston at predetermined positions, as will be more fully described in the following specification and shown inthe accompanying drawings, inwhich- Fig; 1 is a general view showing a typical layout of the control device and an operating valve therefor.

Fig. 2 is a side elevational view of the invention showing the crank moved to neutral position with the pressure stillonthe cylinder.

Fig. 3 is a half sectional view taken on the line 3-3 of Figure 2.

Fig. 4 is a longitudinal section showing theparts moved to neutral position withthe pressure still in the drawings like characters of reference indicate corresponding parts in each figure.

The numeral I indicates a cylinder block having cylinder heads 2 and 3 and operating cylinders 4. and 5. A double ended piston S is slidable within' the cylinder block I in response. to pressure developed in the cylinders 4' and 5. A rock shaft 1 is mounted transversely of the cylinder block and is fitted on one or both ends with a cam disk 8 and a central crank 9, which crank is connected to the piston 6 by a link ID;

Hingedly' mounted upon pairs of studs 22 are U-shaped levers 23. These levers consist of arms 24 which are connected together by transverse plates 25. The plates 25 are each' provided intermediate their length with an indented: lip 26 for the purpose of receiving an abutment plug 27 of a compression spring 28 which serves to maintain a continuous thrust through the lips 26' on the plates 25 against the plungers 30- of the .piston' 20 to return them" totheir normal retracted position withintheir" cylinders. At the outer end of the plates 25 a latch 32 is pivotally mounted about a pin 35 see-Figure3'. This latch is limited in its movement by extending it through an opening 34 in the arms 24 and is heldin an outward direction by a spring 35. The disk 8 is provided at substantially diametrically opposite points with steps 38 which are selectively adapted to strike one of the latches 32 to bring the shaft l and the piston 6 to rest at the middle of its stroke. Fitted to the shaft 1 is a crank 39 which is coupled through a connecting rod 40 to the reversinggear to be controlled, not shown in the drawings;

A suitable valve arrangement for actuatin the control device could include a twin valve structure 41, see Figure 1 in which valves 42 and 43 are eachprovided with a sliding stem 44 which are adapted to be selectively raised by a swing lever 45. Fluid under pressure is. supplied to the valves 42: and-J3 andiis conducted from thevalves 42' and 43 to. the ported passages. I12 oithe cylinder heads 2 and 3'- respectively through pipes 4'6 and 41; The values 42 and 43' are so designed. that when the-stem: 4'4 of'one of them is raised, fluid will flow under pressure to that valves corresponding operating cylinder, but" as soon as the stem M is allowed to dropto normal position the pressure fl'ow is shut on and the fluid delivered to the cylinder is relieved through the supply pipe-and is allowed toescape through the said valve. The operating lever 45 is shown held to the left with the stem 44 of the valve 42 raised and thepressure on through pipe 46'] to the operating cylinder 4. Thefluid flow inthis direction has entered the-cylinders 4 and Il simultaneously and by virtue of: the larger port [-5, has first exerted a pressure upon the piston- 20 and its plunger 39 therein to urgethe adjacent latch 32 of the arms 24 inwardly so that the plate 25 bears against the periphery of the disk 8 at the low side of the step 38'. The pressure applied to thepiston 5- has caused the disk to rota-tein an anti-clockwise direction until the stephas engaged the latch 32 of the vplate 2-5 asso'ciated 'with the U-shaped levers 23, causing said latch to tension its spring 35 and come to rest at the inner end of its opening as shown in Figure 2. The latch in its tensioned position arrests the rota" tion of the disk and stops the piston 6 in central position Within the cylinder block I and stops the crank 39 in central position, thus setting the reverse gear in neutral position. As soon as the swinging lever 45 is released to assume a vertical position, the valve stem 44 of the valve 52 is released and the pressure within the operating cyl-' inder 4 and the trip cylinder I! is also relieved, allowing the spring 28 to swing the levers 23 to the left of Figures 2 and 4 so that the latch becomes disengaged from the step 38 of the disk and no further movement takes place. If the lever 45 is again swung to the left fluid under pressure will flow again as previously described, but since the latch 32 of the U-shaped lever 23 is at that time withdrawn from the periphery of the disk 8 and said latch has moved outwardly due to tension from its spring 35, said latch cannot again stop the disk, but will be urged to contact the disk above the step as the piston 28 moves in response to the pressure now developed in the trip cylinder l1 and the disk will swing further in an anticlockwise direction to the limit of the piston thrust, thus changing the gear setting to reverse. Obviously swinging the lever 45 to the right will cause fluid pressure flow through the pipe 41 to the ported passage l2 and the cylinders 5 and I8 and will result in the first reciprocation in moving the crank 39 to the neutral position and in the second reciprocation causing it to move to forward position.

It will be noticed that the movement of the piston 6 will be exactly the same distance to neutral whether it moves from reverse or from forward positions and that all movements are positive and substantially instantaneous, and also that with the relatively large area of the piston 6 and the possibility of using any normal air pressure as the motive force, ample force ma be applied to effectively change gear on any size of reverse transmission. The location of the twin valve structure 4| may be at any desired point however remote from the control device and can be relied upon to give instantaneous and trouble free operation.

What we claim as our invention is: 1. A remote control device for changing gears 1 in a marine transmission comprising a pair of aligned cylinders, a piston common to both adapted to be selectively moved in either direction by fluid pressure, a rocking member, operating means between the piston and said rocking member to rock it, separate means for stopping .the movement of the piston in each direction,

means associated with the rocking member for actuating the transmission, and means as the rocking member is rocked to neutral position by fluid pressure applied to one end of the piston for moving one of the stopping means to engage and stop the rocking member against the fluid pressure applied to said piston.

2. A remote control device for changing gear in a marine transmission comprising a pair of when it reaches a predetermined intermediate position of its rocking stroke, each of said latches serving to engage and arrest the rocking member when travelling in one direction only.

3. A remote control device for changing gear in a marine transmission comprising a pair of aligned operating cylinders each having a fluid pressure passage, an operating piston common to both cylinders, a trip cylinder associated with each of the operating cylinders and a piston for each trip cylinder, each trip cylinder piston being adapted to receive an impulse from the fluid in the fluid passage simultaneously with its associated operating cylinder piston, a rocking member adapted to be rocked by either of the operating cylinder pistons, a disk mounted upon the rocking member, said disk having a stop, means for admitting fluid under pressure selectively to one of the operating cylinders and its trip cylinder, and means actuated by the operated trip piston for engaging the stop to arrest the disk and the operating piston at a predetermined point of their respective strokes 4. A remote control device for changing gear in a marine transmission comprising a pair of aligned operating cylinders, each having a fluid pressure passage, an operating piston common to both cylinders, a trip cylinder associated with each of the operating cylinders, and a. piston for each trip cylinder, each trip cylinder piston being adapted to receive an impulse from the fluid in the fluid passage simultaneously with its associated operating cylinder piston, a rocking member adapted to be rocked by either of the operating pistons, a disk mounted upon the rocking member, said disk having a stop, means for admitting fluid under pressure selectively to one of the operating cylinders and its trip cylinder, a sprin retracted swinging arm associated with each trip cylinder, each arm having a latch adapted to swing towards the disk in response to movement of the actuated trip cylinder piston to arrest the disk and the operating piston at a predetermined point of their respective strokes.

5. A remote control device for changing gear in a marine transmission as claimed in claim 4,

said latch being spring tensioned and urged in the direction of the stop of the disk whereby the latch is displaced along the periphery of the disk when engaging the stop to arrest the rocking movement of the disk and said latch is returned by the spring to a point overlying the stop when the pressure is released from the pistons previously actuated thereby.

6. A remote control device for changin gears I in a marine transmission comprising a pair of aligned cylinders, a piston common to both adapted to be selectively moved in either direction by fluid pressure, a rocking member, operating means between the piston and said rocking member to rock it, separate means for stopping the movement of the piston in each direction, means associated with the rocking member for actuating the transmission, and means as the rocking member is rocked to neutral position by fluid pressure applied to one end of the piston for moving one of the stopping means to engage and stop the rocking member against the fluid pressure applied to said piston, and means for removing said stopping means from stoppin position simultaneously with the relieving of fluid pressure from the piston.

7. A remote control device for changing gears in a marine transmission comprising a pair of aligned operating cylinders, a piston common to both adapted to be moved in either direction by 5 6 fluid pressure, a trip cylinder and piston associated with each of the operating cylinders, a REFERENCES CITED rocking member operatively connected with the The following references are of record in the operating cylinder piston, a latch actuated by file of this patent: each trip piston for arresting the rocking mem- 5 her when it reaches a predetermined interme- UNITED STATES PATENTS diate position of its rocking stroke, each of said Number Name Date latches serving to engage and arrest the rocking 524,5 1 Dewson Aug. 14, 1894 member when travelling in one direction only, ,847, 88 Couwenhoven Mar. 1, 1932 and means responsive to a release of pressure 10 ,3 Crittenden Mal. 1943 against the piston for releasing an engaged latch 2,402,419 Larson June 18, 1946 to disengage the rocking member for movement in either direction. FOREIGN PATENTS WELIAM WAGNER. Number Country Date JOHN SWANN, 15 493,652 Great Britain Oct. 12, 1938 

